The need to reduce fuel consumption and emissions in automobiles and other vehicles is well known. Therefore, vehicles are being developed that reduce or completely eliminate reliance on an internal combustion engine. Electrified vehicles are one type of vehicle currently being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles in that they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to drive the vehicle.
Electrified vehicles typically spin down the electric machine when the vehicle is at rest to conserve energy. This can influence the efficiency of subsequent transmission engagements. For example, the transmission pump typically cannot pressurize fast enough to smoothly engage the clutches of the transmission when a shift change is subsequently requested. Although some vehicles may be equipped with auxiliary oil pumps, these pumps lack sufficient capacity to generate the pressure or flow required to perform the initial engagement/filling of the clutches of the transmission. The efficiency of transmission engagements of an electrified vehicle may also be influenced by variations in road grade and vehicle mass.